I get the feeling Rains of Castamere will win simply because votes for Doctor Who will be spread thin amongst the four nominations.
The Hugos don't work that way. They have a complex preference system
where voters rank the nominees and those rankings are analyzed in a way that prevents vote-splitting among similar nominees. That's how Doctor Who
has won most years since 2005, even though it gets so many nominations they might as well change the category name to "Best Doctor Who
Episode or Other Short Dramatic Presentation."